The inventive concept relates generally to electronic circuit technologies. More particularly, certain embodiments of the inventive concept relate to a buck converter, or step-down converter, and related methods of operation.
A buck converter, or step-down converter, is a device used to convert a first voltage into a second voltage of lower magnitude. One of the more common applications of a buck converter is the conversion of a power supply voltage into a lower voltage used to drive an electrical load in a circuit.
FIG. 1 is a block diagram of a conventional bulk converter 10. Referring to FIG. 1, bulk converter 10 comprises a power providing unit 11, a switching unit 12, a current sensor 14, a feedback unit 15, a pulse width modulation (PWM) controller 16, a switch driver 17, and a current detector 18. Bulk converter 10 transfers power VIN from power providing unit 11 to load 13 via switching unit 12. Switch driver 17 controls switching unit 12 based on a combination of inputs produced by the operation of current sensor 14, feedback unit 15, PWM controller 16, and current detector 18, as shown in FIG. 1.
Where load 13 is a relatively small load, current may be lost in a continuous conduction mode (CCM). Accordingly, pulse skipping may be used to prevent this current loss and to improve efficiency. With the pulse skipping, a pulse width modulation (PWM) switching cycle may be skipped according to a power supplied to load 13. That is, the pulse skipping may be used to prevent power from being supplied unnecessarily, Unfortunately, however, the pulse skipping tends to lower the efficiency of the buck converter.